It is known in the art that application of pure water provides an excellent possibility to relax and clean skin. However, there is a need to apply a water reservoir, which can interact with the skin and provide moisture to the skin for a prolonged time period and without the need of immersing or bathing the skin. For this purpose cellulose articles are known, which can be applied in order to provide such water reservoir to the skin.
Particularly, bacterial cellulose materials have been used in medical and cosmetic applications in the prior art. This material is an extracellular polysaccharide produced by different bacteria, including Komatagaibacter, Agrobacter and Sarcina strains (I. F. Almeida et al., Bacterial cellulose membranes as drug delivery systems: An in vivo skin compatibility study, Eur. J. Pharm. Biopharm. (2014)).
Methods for producing bacterial-cellulose are known in the art. Particularly, static or discontinuous production processes, like static fermentation, are used. Particularly, bacterial BNC produced by static or discontinuous production processes is known, however, relatively expensive, and comes along with various drawbacks, particularly with dis-advantageous or at least sub-optimal properties of the produced bacterial cellulose. Moreover, in static manufacturing processes the production of bacterial BNC is limited by the batch-wise production. The bacterial cellulose produced in such processes is of relatively heavy weight and possesses a disadvantageously low tensile strength. A respective article for application to skin, moreover, needs an additional support or other fixation means. Therefore, such articles usually do not allow a subject moving unimpededly while the article remains on the area of skin. Due to the relatively low tensile strength, the articles of the prior art also easily tear. Moreover, many articles known in the art do not provide a sufficient moisturizing effect without wet feeling and a soft and smooth surface feel at the same time.
In Almeida et al. the authors tested skin compatibility of bacterial cellulose patches by applying the patches to the subject's forearms for 24 hours. The patches contained 5% of water and were fixed to the skin using aluminum chambers. One patch contained 32% of glycerin. The glycerin containing patch showed improved bendability.
The document DE 10 2004 002 990 A1 describes a nano-structured material that can be used as a cosmetic pad or wound dressing. It may be used to achieve a cooling effect by evaporation of liquid contained in the material. However, the nano-structured material is rather thin. If thicker material is used, the material needs a supporting structure for reinforcement. In other embodiments, the material is used together with an adhesive or sewn to the skin. However, this document does not disclose an article capable of adhering to the skin without any fixation means or means to support the article's structural integrity. Additional support or fixation means destroy the soft and smooth surface feel of bacterial cellulose films.
The document FR 2 916 971 A1 discloses a slimming composition for application on the thighs including a bacterial cellulose substrate. The substrate includes at least 10% by weight of bacterial cellulose and an active substance. However, even at a very low thickness of only 1 mm, the article does not adhere to the skin without auxiliary measures. Particularly, the substrate should be used together with a support material so that it stays on the skin after application.
The document US 2011/0286948 A1 discloses a bacterial cellulose film that has a density gradient, wherein—when applied to the skin—the part of the film that is in contact with the skin surface has a lower density of microbial fibers than the side facing away from the skin surface. However, the bacterial cellulose film is produced using static fermentation.
The document WO 2007/091801 A1 discloses a bacterial cellulose sheet for use on the burned or otherwise wounded skin. The sheet has absorptive properties towards exudates. The sheet can be soaked with a solution of an active ingredient to obtain a sheet having from 0.5 to 10 mm thickness. The production process uses fruit juice as the cultivation medium. However, the production process is discontinuous and the moisture content of the finished product is very low.
The document US 2013/0244977 A1 teaches a bio-cellulose-containing mask that is produced in a cultivation medium containing ginseng extracts. The sheet is dried after preparation and then impregnated with a cosmetic emulsion. However, the bacterial cellulose is produced in a static process.
The document US 2009/0041815 A1 relates to a cosmetic composition comprising bacterial cellulose and a powder. A method is described in which the bacterial cellulose is brought into contact with the powder and afterwards applied to the skin. However, a support is needed for adhesion of the substrate to the skin. Moreover, the bacterial cellulose is produced using rotating disc fermentation. Such rotating disc fermentation, however, leads to bacterial cellulose having a tensile strength of even less than the bacterial cellulose produced using stationary conditions. The desired advantageous properties according to the present invention, however, are not met.
The document WO 2013/094077 A1 discloses a cosmetic sheet for lips comprising bacterial cellulose, water and at least one non-volatile oil. The sheet is supposed to remain on the lips for 10 seconds to 20 minutes. It is an object of the invention disclosed in that document that the sheet should adhere to the lips. However, treatment time is very short. Moreover, the bacterial cellulose is produced using a static production process, which makes production of the product very expensive, and comes along with further disadvantageous properties of the produced cellulose. It is mentioned that adhesive power of the sheet is sufficient because it contains water. However, this is only true if the thickness of the cosmetic sheet is low and the desired adhesion time is short. It is not disclosed in this document how much water or bacterial cellulose is used in the cosmetic sheet.
The document WO 2012/131623 A2 discloses a fractional cosmetic treatment using a laser and micro needles. It has to be acknowledged that such laser fracturing is a relatively specific treatment and is related to relatively specific needs. The fractional treatment is applied in order to reduce the barrier function of the skin. After fractional treatment an aqueous material is applied. However, the bacterial cellulose is produced in a static process and the use of a support, e.g. a textile wrap, is suggested.
Facial dermatitis, particularly perioral, periorbital, periocular or perinasal dermatitis, is a skin disease characterized by multiple small papules, pustules and vesicles which are localized to the perioral skin around the mouth, perinasal or nasolabial folds around the nostrils, or periocular area around the eyes, respectively. It most commonly affects women between the ages of 20 and 45 years, but may also affect children, men and the elderly. It is common, and has a tendency to recur in individuals who have had it once. Facial dermatitis may be asymptomatic, or may be associated with a burning, stinging sensation in the affected areas. The exact cause of the disease remains un-known. Following over-treatment, the skin is no longer able to produce the necessary fats and lipids, so that it is dry and scaly. The often considerably impaired appearance causes that the affected areas are more intensively treated and cared, and particularly moisturized, whereupon the rash becomes aggravated. Subjects suffering from facial dermatitis usually also increasingly apply cosmetics and skin-care products and, particularly, ointments and crèmes comprising cortisone. These cortisone products initially may achieve an improvement, but this is only short-lived. It is known in the art that the rash, despite further treatment with cortisone, is boosted and intensifies. For an effective treatment, the causes mentioned must be eliminated. In particular, the regular use of cosmetic creams (“moisturizers”) should be avoided. In addition, phototherapy may be applied. During therapy, the affected skin areas may only be cleaned with water. For such treatment, particularly the above-described bio-cellular cellulose articles may be used, which however show the mentioned draw-backs.